US11267501B2 - Steering device anti-rotation assembly - Google Patents

Abstract

A steering column assembly includes a steering shaft operatively coupled to a steering device, the steering shaft and the steering device having corresponding rotation with each other. Also included is an anti-rotation assembly selectively engaged with a surface of the steering shaft to maintain the steering shaft and the steering device in a stationary condition when the steering shaft is rotationally decoupled from road wheels operatively coupled to the steering shaft.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional application of U.S. patent application Ser. No. 15/702,159, filed Sep. 12, 2017, the disclosure of which is incorporated by reference herein in its entirety.

BACKGROUND

The following description relates to steering column assemblies and, more particularly, to a steering device anti-rotation assembly.

As the automotive industry moves toward autonomously driven vehicles, there will be Advanced Driver Assist Systems (ADAS) that allow a vehicle to be autonomously controlled using sensing, steering, and braking technology. Implementing steering on ADAS vehicles may include decoupling the driver interface (e.g., steering wheel) from the steering actuator. However, a rotating driver interface may cause confusion, inconvenience or even harm to the driver during an autonomous driving mode. Even while decoupled, inadvertent rotation of the driver interface may occur due to vibration, friction, and gravitational imbalance, for example. Addressing the issue of a moving interface will assist with the overall development of autonomous vehicle technology and feasibility.

Some concepts associated with preventing rotation of a driver interface involve mechanical interlocks that require the steering wheel to be positioned in a single specific position or one of a finite, limited number of angular positions in order to facilitate locking. These concepts may be problematic because to initiate a locked wheel, the steering wheel must be first aligned with one of these specific angular positions. In addition, there may be difficulty engaging and/or disengaging the locking mechanism.

SUMMARY

According following description relates to steering column assemblies and, more particularly, to a steering device anti-rotation assembly. As the automotive industry moves toward autonomously driven vehicles, there will be Advanced Driver Assist Systems (ADAS) that allow a vehicle to be autonomously controlled using sensing, steering, and braking technology. Implementing steering on ADAS vehicles may include decoupling the driver interface (e.g., steering wheel) from the steering actuator. However, a rotating driver interface may cause confusion, inconvenience or even harm to the driver during an autonomous driving mode. Even while decoupled, inadvertent rotation of the driver interface may occur due to vibration, friction, and gravitational imbalance, for example. Addressing the issue of a moving interface will assist with the overall development of autonomous vehicle technology and feasibility.

Some concepts associated with preventing rotation of a driver interface involve mechanical interlocks that require the steering wheel to be positioned in a single specific position or one of a finite, limited number of angular positions in order to facilitate locking. These concepts may be problematic because to initiate a locked wheel, the steering wheel must be first aligned with one of these specific angular positions. In addition, there may be difficulty engaging and/or disengaging the locking mechanism.

BRIEF DESCRIPTION OF THE DRAWINGS

The subject matter which is regarded as the invention is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:

FIG. 1 is a schematic illustration of an embodiment of a steering system, including a steering column assembly;

FIG. 2 is a schematic illustration of an embodiment of a steering system, including a steering column assembly;

FIG. 3 is a schematic illustration of an embodiment of a steering system, including a steering column assembly;

FIG. 4 is a steering device anti-rotation assembly according to an aspect of the disclosure;

FIG. 5 is a steering device anti-rotation assembly according to another aspect of the disclosure shown, the steering column assembly shown in an extended position;

FIG. 6 illustrates the steering device anti-rotation assembly ofFIG. 5, the steering column assembly shown in a retracted position; and

FIG. 7 is a schematic illustration of an embodiment of the steering system, including a steering column assembly.

DETAILED DESCRIPTION

Referring now to the Figures, where the invention will be described with reference to specific embodiments, without limiting same, various features of a steering column assembly for an autonomous vehicle are illustrated. As described herein, the embodiments provide a reliable and efficient assembly that maintains a steering device in a stationary position while the vehicle is operating in an autonomous or semi-autonomous driving mode. The steering device is referred to herein as a steering wheel (i.e., hand wheel), but it is to be appreciated that any device used to steer a vehicle would benefit from the embodiments described herein. For example, knobs, joysticks, etc. may be encompassed by the term “steering device.”

The steering column assembly is part of an advanced driver assist system (ADAS) that is able to steer as well as control other parameters of the vehicle to operate it without direct driver involvement. Autonomous or semi-autonomous driving refers to vehicles that are configured to perform operations without continuous input from a driver (e.g., steering, accelerating, braking etc.) and may be equipped with technology that allows the vehicle to be autonomously or semiautonomously controlled using sensing, steering, and/or braking technology.

Referring toFIGS. 1-3, schematic illustrations of various embodiments ofsteering systems10, including steering column assemblies are shown. Thesteering systems10, including steering column assembly described herein may be an electric power steering system, such as the embodiments shown inFIGS. 1 and 2. In these embodiments, a steering device, referred to as asteering wheel12, is operatively coupled to afirst steering shaft14, with one or more additional steering shafts16 (e.g., intermediate shaft) directly or indirectly coupled to thefirst steering shaft14. Asteering actuator18 provides steering assist and/or feedback to a driver during manual driving. Adecoupling mechanism20, such as a clutch mechanism or the like, selectively couples and decouples thesteering wheel12 from thesteering actuator18,road wheels19, etc., at adecoupling location22. As shown inFIGS. 1 and 2, the location of thesteering actuator18 at least partially determines the location of thedecoupling location22. For example, inFIG. 1, thesteering actuator18 is in the passenger compartment of the vehicle and coupled to thefirst steering shaft14. In such an embodiment, thedecoupling location22 is along thefirst steering shaft14 or between thefirst steering shaft14 and an additional shaft that is directly coupled to thesteering wheel12. In the example ofFIG. 2, thesteering actuator18 is outside of the passenger compartment (e.g., under the vehicle hood). In such an embodiment, thedecoupling location22 may be along the first steering shaft14 (as shown inFIG. 2) or along the one or more additional shafts16 (as shown inFIG. 7).

FIG. 3 illustrates another example of thesteering system10, including a steering column assembly that facilitates decoupling thesteering wheel12 from theroad wheels19. In the illustrated embodiment, a steer-by-wire system includes an electrical connection betweensteering shaft14 and theroad wheels19. In other words, a continuous mechanical structural relationship is not present between thesteering shaft14 and theroad wheels19. In this embodiment, aroad emulator24 is operatively coupled to thesteering shaft14 to transmit steering commands from thesteering shaft14 to theroad wheels19 and to provide road feedback to the driver in a manual driving mode. The decouplinglocation22 is between thesteering wheel12 and theroad emulator24 in this embodiment.

The precedingexemplary steering systems10, including steering column assemblies, facilitate selective coupling and decoupling between thesteering wheel12 and theroad wheels19, which is desirable for a vehicle equipped with autonomous or semi-autonomous driving capabilities. In a manual driving mode that requires manual inputs from a driver to steer theroad wheels19, thesteering wheel12 is coupled to theroad wheels19. In an autonomous driving mode that does not require manual inputs from the driver to steer theroad wheels19, thesteering wheel12 is decoupled from theroad wheels19. The decoupled (or rotationally decoupled) condition results in independent rotation of thesteering wheel12, such that rotation of road wheel angular movement does not require or result in corresponding rotation of thesteering wheel12.

Each of the embodiments shown inFIGS. 1-3 include ananti-rotation assembly30 that prevents inadvertent rotation of thesteering wheel12 in the autonomous driving mode, where thesteering wheel12 is in the decoupled condition. Inadvertent rotation may occur for a variety of reasons, including but not limited to vibration, friction, gravitational imbalance, etc. Maintaining thesteering wheel12 in a stationary position reduces the likelihood of driver confusion, inconvenience and/or harm. Placing thesteering wheel12 in the stationary position occurs upon transition to the decoupled condition of thesteering system10.

As described herein, theanti-rotation assembly30 does not require a specific radial orientation to engage and disengage, as is the case with other devices that involve interlocks with mechanical engagement to teeth, slots or the like. Interlocking devices require the steering wheel to be positioned in one of a finite, limited number of angular positions in order to lock, which may require considerable force to retract the lock pin, or the like, when there is torque on the steering wheel.

Referring now toFIG. 4, an embodiment of theanti-rotation assembly30 is illustrated in more detail. The steeringshaft14 includes acontact surface region32 that extends at least partially around the outer circumference of the steeringshaft14. In the illustrated embodiment, thecontact surface region32 extends completely (i.e., 360 degrees) around the outer circumference of the steeringshaft14. Thecontact surface region32 is selectively contacted, or engaged, with afriction shoe34 to prevent rotation of the steeringshaft14 and consequently thesteering wheel12. Thefriction shoe34 has acontact engagement surface36 that has a radius of curvature that substantially contours to thecontact surface region32 of the steeringshaft14.

Thefriction shoe34 is operatively coupled to, or integrally formed with, an actuator38. The actuator38 may be any type of actuator, including electric, pneumatic, hydraulic, etc. In these actuator examples, the actuator38 is in operative communication with acontroller40 that commands engagement or disengagement between thefriction shoe34 and the steeringshaft14 based on the driving mode of the vehicle and whether thesteering column assembly10 is in the coupled condition or the decoupled condition. Thecontroller40 may be in operative communication, or be part of, an advanced driving assist steering (ADAS) system. Alternatively, the actuator38 may be manually controlled by the driver with a lever or the like.

Thefriction shoe34 is moved into engagement or disengagement with the steeringshaft14 with any suitable driving structure that is coupled to, or part of, the actuator38. In the illustrated embodiment, apin42 extends between the actuator38 and thefriction shoe32. Extension of thepin42 forcibly drives thefriction shoe34 into contact with thecontact surface region32 of the steeringshaft14 and retraction of thepin42 discontinues contact between the steeringshaft14 and thefriction shoe32.

As described above, inadvertent rotation of thesteering wheel12 and steeringshaft14 may occur even in the decoupled condition. The frictional contact between thefriction shoe34 and the steeringshaft14 is sufficient to maintain the steering wheel radial orientation, in any radial position, during autonomous driving operation. The stationary condition may be achieved regardless of the telescope position of thesteering wheel12 and minimum force is required to disengage theanti-rotation assembly30 when exiting the stationary condition.

Referring now toFIGS. 5 and 6, another embodiment of the anti-rotation assembly is illustrated and generally referenced withnumeral130. Theanti-rotation assembly130 includes afriction disk132 operatively coupled to the steeringshaft14 or thesteering wheel12. Thefriction disk132 extends completely around the outer circumference of the steeringshaft14.

As shown with arrow A, thesteering column assembly10 generally, and more specifically thesteering wheel12, is translatable between an extended position (FIG. 5) and a retracted position (FIG. 6). The extended position corresponds to a range of positions that are associated with a range of driving positions that comfortably allow a driver to steer the vehicle in the manual driving mode. This position may be referred to as an un-stowed position. The retracted position corresponds to one or more positions that are located further away from the driver than positions commonly associated with manual driving and may be referred to as a stowed position(s). In the retracted position, thesteering wheel12 is located in close proximity to a vehiclestationary structure134. The close proximity includes embodiments where a distance is between thesteering wheel12 and the vehiclestationary structure134 and embodiments where thesteering wheel12 is in contact with the vehiclestationary structure134, including retracted within thestructure134. The vehiclestationary structure134 may be any structure that is substantially stationary relative to the vehicle. For example, the vehiclestationary structure134 may be an instrument panel or a cross-car beam. These are merely illustrative and it is to be understood that other vehicle structures may be employed. Regardless of the precise structure that is the vehiclestationary structure134, afriction pad136 is operatively coupled thereto. Thefriction disk132 and thefriction pad136 are positioned such that they are in frictional contact when thesteering wheel12 is disposed in the retracted position. The frictional contact between thefriction disk132 and thefriction pad136 is sufficient to maintain the steering wheel radial orientation, in any radial position, during autonomous driving operation.

Although theanti-rotation assembly130 illustrated and described above has thefriction disk132 operatively coupled to thesteering wheel12 or the steeringshaft14 and thefriction pad136 operatively coupled to the vehiclestationary structure134, it is to be appreciated that the reverse configuration may be provided in some embodiments.

As with the embodiment ofFIG. 4, theanti-rotation assembly130 facilitates frictional engagement at any radial position of thesteering wheel12 upon retraction. Additionally, theassembly130 does not require any additional actuator, as retraction and extension of thesteering wheel12 engages and disengages theanti-rotation assembly130.

While the present disclosure has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the present disclosure is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the scope of the present disclosure. Additionally, while various embodiments of the present disclosure have been described, it is to be understood that aspects of the present disclosure may include only some of the described embodiments or various combinations of the described embodiments. Accordingly, the present disclosure is not to be seen as limited by the foregoing description.

Claims (7)

Having thus described the invention, it is claimed:

1. A steering column assembly comprising:

a steering shaft operatively coupled to a steering device, the steering shaft and the steering device having corresponding rotation with each other, the steering device translatable to a retracted position in an autonomous driving mode, the retracted position placing the steering device proximate a vehicle stationary structure; and

an anti-rotation assembly to maintain the steering shaft and the steering device in a stationary condition when the steering device is in the retracted position, the anti-rotation assembly comprising:

a friction disk operatively coupled to one of the steering shaft and the vehicle stationary structure; and

a friction pad operatively coupled to one of the steering shaft and the vehicle stationary structure, the friction disk and the friction pad being operatively coupled to different components, the friction disk and the friction pad in contact when the steering device is in the retracted position to maintain the steering device in the stationary condition.

2. The steering column assembly ofclaim 1, wherein the friction disk extends completely around a circumference of the steering shaft.

3. The steering column assembly ofclaim 1, wherein the vehicle stationary structure is an instrument panel.

4. The steering column assembly ofclaim 1, wherein the vehicle stationary structure is a cross-car beam.

5. The steering column assembly ofclaim 1, wherein the steering column assembly is part of an electric power steering system.

6. The steering column assembly ofclaim 1, wherein the steering column assembly is part of a steer-by-wire steering system.

7. The steering column assembly ofclaim 1, wherein the steering column assembly is part of an advanced driving assist steering (ADAS) system.

Images